Universal die set with quick change die plates

ABSTRACT

A PRESS HAS AN UPPER SHOE AND A LOWER SHOE AND THERE ARE OPPOSITELY-DISPOSED AIR CYLINDERS ON EACH SHOE WHICH OPERATE STRAIGHT LINE CLAMPS TO MOVE THE LATTER HORIZONTALLY TOWARD AND AWAY FROM EACH OTHER, EACH CLAMP HAVING A TAPERED SURFACE FOR COCTION WITH SIMILARLY TAPERED SURFACES ON OPPOSITE SIDES OF THE DIE PLATE TO MOVE THE LATTER VERTICALLY INTO OPERATIVE POSITION ON ITS SHOE AND TO HOLD IT TIGHTLY CLAMPED IN SAID POSITION, THE PLATES BEING SUPPORTED FOR SLIDING MOVEMENT INTO AND OUT OF THE SHOE WHEN THE CLAMPS ARE IN NON-CLAMPING POSITION.

D. c. HOPPER 3,610,021

UNIVERSAL DIE SET WITH QUICK CHANGE DIE PLATES Oct. 5, 197] 2 Sheets-Sheet 1 Filed March '7, 1969 QMK QMWN

a v \Wm INVE NTOR DUANE C. HOPPER ATTORNEYS D. c. HOPPER 3,

UNIVERSAL DIE SET WITH QUICK CHANGE DIE PLATES Oct. 5, 1971 Filed March '7, 1969 2 Sheets-Sheet 2 INVE NTOR DUANE C. HOPPER AT TORN EYS United States Patent 3,610,021 UNIVERSAL DIE SET WITH QUICK CHANGE DIE PLATES Duane C. Hopper, Lake Geneva, Wis., assignor to Albert Trostel Packings Ltd., Lake Geneva, Wis. Filed Mar. 7, 1969, Ser. No. 805,266 Int. Cl. B21j 13/02 US. Cl. 72-446 8 Claims ABSTRACT OF THE DISCLOSURE A press has an upper shoe and a lower shoe and there are oppositely-disposed air cylinders on each shoe which operate straight line clamps to move the latter horizontally toward and away from each other, each clamp having a tapered surface for coaction with similarly tapered surfaces on opposite sides of the die plate to move the latter vertically into operative position on its shoe and to hold it tightly clamped in said position, the plates being supported for sliding movement into and out of the shoe when the clamps are in non-clamping position.

BACKGROUND OF THE INVENTION Filed of the invention The present invention is particularly useful in the mounting and replacing of die plates in the shoes of a punch press. The invention is, however, suitable for use in clamping various tool-carrying plates or workpieces in position in various types of forming machinery.

Description of the prior art Heretofore the setting up of the dies in a press has been a time-consuming operation because of the weight and clumsiness of the parts which must be handled, and because of the time necessary in manipulating the various setup blocks, clamps, T-bolts, and slide nuts which is usually involved. These prior setup procedures customarily take an hour or more. There is a device on the market wherein there are vertically movable clamps which, when operated, push the die plates into and out of operative position. These vertically movable clamps must be operated by other devices which move at right angles to the clamps and there has to be means for translating the horizontal motion into vertical motion. This prior attempt to simplify the setup procedure is relaively complicated and expensive to manufacture.

SUMMARY OF THE INVENTION The present invention provides, in a machine having upper and lower shoes, oppositely-disposed air cylinders for each shoe which operate straight line clamps to move the latter horizontally, there being guides for slidably receiving the die plates and for temporarily supporting the same, and each plate having oppositely-disposed tapered surfaces which are engaged by similarly tapered surfaces on the clamps so that the temporarily-supported die plate is moved vertically into operative position by the horizontally movable clamps, the clamps being directly carried by plungers of said cylinders and operated directly to move the die plates without the use of intervening mechanisms.

A general object of the invention is to provide a universal die set wherein the die plates may be quickly changed and replaced in a matter of minutes.

A further object of the invention is to provide a universal die set having novel clamping members and having other means for accurately guiding the plates into proper operative position while the clamps are being operated.

A further object of the invention is to provide mecha- Patented Oct. 5, 1971 "ice BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings illustrating one complete embodiment of one adaption of the invention in which the same reference numerals designate the same parts in all of the views:

FIG. 1 is a transverse vertical section through a punch press, the air cylinder cushions being indicated diagrammatically;

FIG. 2 is a view taken approximately on the line 22 of FIG. 1 looking upwardly at the bottom of the top shoe assembly, parts being broken away and shown in section, the view showing only one side of the assembly, the other side being identical except that it is reversed in position; and

FIG. 3 is a view taken approximately on the line 3-3 of FIG. 1 looking downwardly on the top of the bottom shoe assembly, the view showing only one side of the assembly, the other side being identical except that it is reversed in position.

DESCRIPTION OF THE PREFERRED EMBODIMENT For purposes of illustration the device has been shown as it is used in a punch press which is suitable for blanking and piercing large washers, or for the deep drawing of cases up to eight inches in diameter. It is to be understood, however, that the invention is suitable for use in many other forming machines in holding plate-supported tools or workpieces in operative position in a manner permitting quick replacement.

The numeral 10 designates an upper shoe, the latter being supported for up and down reciprocal movement under the influence of an hydraulic actuator or by other means. Suitably connected to opposite sides of the shoe are fluid pressure operated devices such as air cylinders 12 which are identical in structure but which face toward one another. Each air cylinder has the usual piston therein from which a plunger 13, which is connected to a slidable clamp 14, projects. Each clamp is U-shaped in plan view as shown in FIG. 2, having legs 15 which are slidable on guides 16. Each guide 16 is secured by dowels and bolts 17 and 18 to the shoe. Springs 19 have one end received in recesses 20 of the legs 16 of the clamping members 14. The other ends of the springs are accommodated in pockets 21 in end blocks 22. The springs normally urge the clamping members to an extended position.

A replaceable tool or work-holding plate 23, which, in the case of the punch press illustrated, is a die-holding plate, has opposite surfaces of its underside equipped with wear plates 24 having tapers 25. In the case of a plate in a punch press it may be equipped with the usual stripper ring 26 which is mounted on the lower ends of slidable studs 27 having top heads 28 which limit downward movement of the stripper ring. Springs 29 surrounding the studs 26 between the ring and the lower face of the plate 23 normally urge the stripper ring in a downward direction. The plate is also equipped with a central slidable pin 30 carrying a knockout member 31 on its lower end, as is customary in punch press plates. The plate 23 is also provided with a plurality of equally spaced locating holes 32 which are lined with bushings 33 and which are adapted to receive the lower ends of locating pins 34 which project from the underside of the shoe 10.

Secured to the underside of the shoe by bolts 35 are spaced guide bars 36. These guide bars are spaced apart just the proper distance to slidably receive the plate 23, the back of the plate, when it is fully inserted, engaging stop rods 37 (see FIG. 2). During slidable insertion of the plate 23 the heads of the bolts 28 are received in grooves 38.

The upper sides of the clamping members 14 are shaped as at 39 to receive the guide bars 36' between the back wall portion 40 of each clamping member and the side edge of the plate 23. In addition, the lower face of each guide bar is tapered as at 41 to avoid interference with the clamping member. The plate 23 may carry any suitable forming tool. In the illustration it is a blank drawing ring 42 which is adapted to stamp out and form a cup 43 from a flat sheet of metal, leaving scrap rings 44 and 45. The metal is formed and cupped with the aid of a die 46 and a blanking ring 47 which are suitably supported on the top of a bottom die plate 123, there being the usual ring-shaped floating pressure pad 48 between the die member 46 and the blanking ring 47.

The bottom shoe assembly is very similar to the top shoe assembly except that the plate 123 and associated parts are positioned on the top instead of underneath, and all of the corresponding parts are designated by the same numerals as are used in the top shoe assembly except that they are preceded by the digit 1. These corresponding parts will not be redescribed.

The clamping members 114 for the bottom shoe assembly, of course, have their tapered surfaces 139 facing downwardly, and the bottom clamps are somewhat heavier in thickness. In addition, the guide bars 136 on the bottom, which correspond to the guide bars 36 on the top, are resiliently mounted in recesses 149 on springs 150 so that when the plate 123 is in the clamped, full line position of FIG. 1 the upper surfaces 151 of the guide bars 136 are flush with the upper surface of the shoe. Also, each guide bar has an outer rail 152 which projects above the surface of the shoe 110 when the plate 123 is in clamped position. When the clamping members 1.14 are in withdrawn position, as indicated by dotted lines in FIG. 1, then the springs urge the guiding bars 136 to the dotted line, elevated position, in which position they slidably receive the plate 123.

Operation and use In use of the above mechanism, with the shoe assemblies separated, the clamping members are retracted by admitting compressed air from a suitable source into the inlets 53 and 153. This air flows through ducts 54 and 154 into the ends of the cylinders which face the work to act on the usual pistons in the cylinders 12 to retract the plungers 13 and 113 and cause the clamping members 14 and 114 to be retracted. When in the retracted position shown by dotted lines in FIG. 1, the die plates 23 and 123 may be readily withdrawn for replacement. The upper die plate 23 will have its tapered surface sliding on projecting portions of the tapered faces 39 of the clamping members, which faces are still partially overlapped when withdrawn. Due to the retracted position of these tapered faces 39 the plate has dropped away from the undersurface of the upper shoe 10 a suflicient distance to move the upper ends of the locating holes 33 below the lower ends of the locating pins 34. The plate 23 can then be readily slid out for replacement.

When the clamping members 114 on the bottom assembly are in retracted condition, the springs 150 cause the guide bars 136 to push the lower die plate 123 upwardly a suflicient distance to free the locating holes 133 from plate with attachments may then be readily slid out.

The new die members are slid into position by a reverse procedure, and the compressed air is then directed into the other inlet ports .55 and 155 to act on the piston within the cylinders 12 and 112 to cause the clamping members 14 and 114 to be extended. In the case of the upper die plate 23, before extension of the clamping members 14, the plate is supported between the two guide bars 36 and on the overlapped portions of the tapered surfaces 39 of the retracted clamping members 14. With the plate pushed all the way in into engagement with the back pins 37, the locating holes 33 will be directly below the lower ends of the locating pins 34. Then when the clamping members 14 are extended they will act on the tapered faces 25 on opposite sides of the die plate 23 to cause movement of the die plate in a direction at right angles to the direction of the movement of the clamping members. During such movement the lower ends of the locating pins 34 enter the locating holes 33 to accurately locate the die plate 23 on the upper shoe. When the clamping members 14 are fully extended to the position shown in full lines in FIG. 1, the upper die plate 23 is tightly clamped against the lower surface of the upper shoe 10.

In the case of the lower shoe assembly, when the clamping members 114 are in withdrawn position the spring loaded guide bars 136 are elevated so that when the new bottom die plate 123 is slid into position on the upper ends of the guide bars 136 it will be just above the upper ends of the locating pins 134 so that they will not interfere. When air pressure is directed into the inlets 155 of the bottom cylinders it will act on the pistons in the bottom cylinders to cause extension of the plungers 113 and extension of the clamping blocks 114. During such extension movement the downwardly-facing tapered surfaces 139 of the clamping members 114 will act on the tapered surfaces on opposite sides of the bottom die plate 123. This will cause downward movement of the die plate 123 at right angles to the direction of movement of the clamping members 114. During such downward movement the guiding bars 136 will be pushed downwardly against the action of the springs to the full line position shown in FIG. 1. During such movement the locating pins 134 will enter the locating openings 133 of the plate 123 to accurately position said die plate on the bottom shoe. When the clamps 114 are in fully extended position the die plate 123 will be firmly clamped against the upper surface of the bottom shoe 110.

From the above it is apparent that the die plates 23 and 123 may be quickly replaced and accurately located for a new operation. With a conventional die press a setup of this type took between forty-five minutes and an hour and one-half. With the present invention such setup may be performed in as short a time as five to ten minutes, and in such period both of the die plates will be accurately located and firmly clamped in position.

The operation of the press is conventional. With the upper shoe raised a flat blank is placed on top of the blanking ring 47 and die 46. Then the upper shoe 10 is forcibly lowered to cause the outer periphery of the blanking ring 18 to cut out the work, leaving the piece of scrap 44. Upon further closing movement of the press the cut material will be cupped as at 43, and eventually the rim of the cup will be trimmed, leaving another ring of scrap 45. During such closing movement the floating pressure pad 48 is pushed downwardly to the position shown in FIG. 1. Also, during operation the bottom die plate is under the influence of a bottom cushion 156 acting as indicated by the arrows. Such bottom cushion is usually actuated by an air cylinder which exerts a predetermined amount of pressure on the bottom shoe 110 in an upward direction. Such bottom air cylinder cushions are conventional and have only been illustrated diagrammatically. After the upper shoe is raised the dies become separated from the condition of FIG. 1 and the knockout member 46 is operated to knock out the work 43.

Also, the floating pressure pad 48 will knock out the scrap ring 45, and the stripping ring 26 will knock out the scrap ring 44.

I wish it to be understood that I do not desire to be limited to the exact details of construction shown and described, for obvious modifications will occur to a person skilled in the art.

I claim:

1. In a forming machine having a support, a tool carrying plate having oppositely-disposed tapered surfaces, guide means on said support for slideably guiding said plate into partially-assembled position, oppositely-disposed clamping members mounted for extensible and retractible movement toward and away from one another and having tapered surfaces disposed to engage the tapered surfaces of the plate, and means for forcibly moving said clamping members into engagement with said tapered surfaces of the plate to move the plate at right angles to the direction of movement of the clamping members, thereby clamping the plate in operative position on the support, the tapered surfaces being on opposite sides of the plate, and the guide means including spaced guide bars adjacent opposite sides of the plate between which the plate is received, said clamping members, when in retracted position, also serving to support the plate while it is being slid into position between the guide bars.

2. In a forming machine having a support, a toolcarrying plate having oppositely-disposed tapered surfaces, guide means on said support for slideably guiding said plate into partially-assembled position, oppositelydisposed clamping members mounted for extensible and retractible movement toward and away from one another and having tapered surfaces disposed to engage the tapered surfaces of the plate, and means for forcibly moving said clamping members into engagement with said tapered surfaces of the plate to move the plate at right angles to the direction of movement of the clamping members, thereby clamping the plate in operative position on the support, there being cooperating locating means on the support and plate which are aligned when the plate has been slid into partially-assembled position, and the clamping members, when being moved to clamping position, also acting to cause engagement of said locating means, the tapered surfaces being on opposite sides of the plate, and the guide means includes spaced guide bars adjacent opposite sides of the plate between which the plate is received, said clamping members, when in retracted position serve to support the plate while it is being slid into position between the guide bars.

3. A forming machine as claimed in claim 1 in which the support is the top shoe of a punch press, and in which the spaced guides are on the underside of said shoe, and in which the retracted clamping members have their tapered surfaces located to support a partially-assembled plate against the action of gravity.

4. A forming machine as claimed in claim 1 in which the support is the bottom shoe of the punch press and has upstanding locating pins, in which the tool-carrying plate is the bottom die plate of a punch press and has locating holes positioned to receive the locating pins, in which the spaced guides have body portions extensibly recessed in the top surface of said shoe, which body portions have upper ends shaped to slideably support the plate, and in which there is spring means normally urging said spaced guides upwardly a sufficient distance so that the plate may be slid into position without interference from the locating pins.

5. A forming machine as claimed in claim '1 in which the engaging surface of each clamping member is shaped to embrace the adjacent guide bar when the clamping member is in clamping position.

6. In a forming machine having an upper support, a tool-carrying plate disposed below said support and having oppositely-disposed tapered surfaces, oppositely-disposed clamping members mounted for extensible and retractible movement toward and away from one another and having tapered surfaces disposed to engage the tapered surfaces of the plate, and means for forcibly moving the clamping members into engagement with said tapered surfaces of the plate to move the plate at right angles to the direction of movement of the clamping members, thereby clamping the plate in operative position below the support, the tapered surfaces being on opposite sides of the plate and the clamping members, when in retracted position, being in a position to support the plate against downward movement by gravity while it is being slid into preliminary position.

7. A forming machine as claimed in claim 6 in which the means for forcibly moving the clamping members comprises oppositely-disposed fluid pressure operated rams, and in which there is spring means disposed to normally urge said clamping members to fully-extended clamping position as a safety feature in case fluid pressure should be lost in the rams.

8. A forming machine as claimed in claim 6 in which there is a lower support positioned opposite said upper support and having upstanding locating pins, a lower toolcarrying plate supported on top of said lower support and having oppositely-disposed tapered surfaces and having locating holes positioned to receive the locating pins of the lower support, spaced guides extensibly recessed in the top surface of said lower support having upper ends shaped to slideably support the bottom plate, spring means normally urging said spaced guides upwardly a sufficient distance so that the plate may be slid into position without interference from the locating pins, clamping members mounted on said lower support for extensible and retractible movement toward and away from one another and having tapered surfaces disposed to engage the tapered surfaces of the plate, and means for forcibly moving the clamping members into engagement with said tapered surfaces of the plate to move the plate at right angles to the direction of movement of the clamping members and downwardly against the lower support, thereby clamping the plate in operative position on said support.

References Cited UNITED STATES PATENTS 2,913,946 11/1959 Ellrich 83630 3,104,574 9/1963 Anderson 83167 3,225,686 12/1965 Clements 10O43 3,230,869 12/1966 Wilkins 214 3,332,308 7/1967 Keen 83---698 3,422,660 1/1969 Countess 72448 3,422,661 1/ 1969 Blackhurst 72448 FOREIGN PATENTS 1,194,227 6/1965 Germany 72-446 CHARLES W. LANHAM, Primary Examiner G. P. CROSBY, Assistant Examiner US. Cl. X.R.

72470; 83--698; 100DIG. 18 

